The recent arrivals in North America of SARS and monkeypox have understandably alarmed us all. But they should not have surprised us. We already knew that an inevitable side effect of globalization is that emerging infectious diseases can spread more rapidly. We already knew that many human diseases have their origin in close contact between people and domesticated animals. Those considerations have informed public health policy for decades.p. What hasn’t been adequately considered — despite persistent warnings — is the dramatic increase in global trade in alien animals and plants, and the accidental transport of other species in ships and planes. Once here, such alien species pose not only a threat to humans, but can destroy our crops, wildlife and natural ecosystems o and may be far more costly in the long run than most forms of pollution. Unlike air and water pollution, which are often correctable, biological invasions are usually irreversible, for the simple fact that alien organisms reproduce.p. Thus the Fish and Wildlife Service and other federal agencies can no longer afford to ignore the dangers posed by Chinese carp being sold in live food markets in major American cities, and by Gambian rats and prairie dogs being sold in Midwestern pet stores. The recent embargo by Tommy G. Thompson, the secretary of health and human services, on the importation of rodents from Africa is only a reactive step. What is required are broader preventative policies.p. The problem is that the left and right hands of the federal government are uncoordinated. The Centers for Disease Control and the Department of Agriculture do an admirable job of protecting us and our crops against obvious and direct health threats. However, other branches, like the Interior Department, have not yet awakened to the more insidious dangers that alien species pose to wildlife and natural ecosystems. Think, for example, of how Dutch elm disease and chestnut blight wiped out our native elm and chestnut trees last century, or of how our native oysters have been devastated by alien predators and disease. In aggregate, the cost of alien species to the United States economy has been estimated at $137 billion per year.p. In 2001, the government’s own National Invasive Species Council — with input from the invasive species advisory committee on which I serve — produced an ambitious plan to correct these problems, including steps to develop screening protocols to prevent the importation of harmful species. Unfortunately, the council has little authority to push through the plan. Instead, its recommendations have become bogged down in federal bureaucracy and few have been implemented.p. Congress needs to increase the authority of the council, and to pass legislation like the National Aquatic Invasive Species Act of 2003 to move forward urgent research and governmental efforts to prevent future invasions.p. Surprising or not, the arrivals of SARS and monkeypox are nothing short of a screeching alarm. We can no longer separate human health from the health of other organisms and our ecosystems. Every day, the pet trade and unintentional pathways like the ballast water of ships bring thousands more hitchhiking species into our country. Unless government agencies work together, SARS and monkeypox could be just the beginning.p.
David M. Lodge is a biologist at the University of Notre Dame. p. p. June 19,2003